1. Field of the Invention
The present invention relates to an apparatus for presenting a test chart, which presents a test chart used for testing a visual performance, and more particularly to an apparatus for presenting a test chart suitable for a test in near vision.
2. Description of Related Art
In a visual performance test for a refractive power of an eye to be examined or the like, an apparatus for presenting a test chart, which presents various kinds of test charts, is used, such apparatus is classified into an apparatus for far vision and an apparatus for near vision.
The apparatus for near vision commonly has a simple construction, for example, such apparatus is known that holds a plate in the shape of a disk, which is provided with a plurality of test charts, in a case in the shape of a plate, which is provided with a test chart window, so that the plate may rotate. Referring to the apparatus, if an operator rotates the plate by operating, then the test charts are changed-over and placed in the test chart window.
The operator has to understand details of the test charts and the method of use thereof prior to a test in order to test accurately, however, the test chart differs with manufacturers or type of the apparatus, therefore, it is difficult for the operator to memorize all of them. However, if the test is performed with confirming a manual, a guide book or the like, then it takes much time and disables the operator for smooth test. Further, if the operator loses the manuals or the like, then hindrance may be occurred in the case of an unskilled operator not understanding details of test charts sufficiently.
In addition, there is known such apparatus that has a plate provided with a character denoting its testing distance, as well as test charts, peripherally, however, this character is unnecessary for presentation to the examinee. Moreover, if the examinee gaze at the character, then the eye of the examinee is not fixed to a certain point, as a result, it takes much time to perform the test.